Renal sympathetic denervation improves heart rate variability and reduces arrhythmia burden

Abstract

Abstract Background Decreased heart rate variability (HRV) is a strong predictor of mortality (particularly sudden death), not only in high-risk patients. The impact of renal denervation (RDN) on HRV and cardiac arrhythmias has not yet been fully investigated. Purpose To assess the effect of RDN on HRV and cardiac arrhythmias in patients with blood pressure (BP) >160/100 mmHg despite 3 full-dose antihypertensive drugs. Methods The study included 108 patients (46.3% male) with resistant hypertension (RH), the average age was 50.5±9.0. All patients underwent RDN. Procedure was performed by an experienced electrophysiologist at the renal arteries using specialized electrode Symplicity Flex: ablation power = 8–10 W at 55°C, 4–10 points for each renal artery (including brunch, when was appropriate), 2 minutes per point. Office systolic BP (SBP) and diastolic BP (DBP), 24-hour ambulatory BP monitoring and 24-hour monitoring ECG were measured before, at 6 and 12 months of follow-up. Results Baseline SBP and DBP in these groups of patients were −185.6±29 and −110.5±19.3 mm Hg respectively. Office BP significantly decreased by −28.2±21.6 /18.0±16.7 mm Hg (p<0.001 for both) at 12 month. 24-hour SBP and DBP was significantly reduced both at 6 and 12 months after RDN. Twenty-four-hour BP was reduced by 13.2/8.4mmHg (P<0.001). The number and dosage of antihypertensive drugs remained unchanged in all patients. Baseline data of general HRV in this group of patients were low: SDNN – 123.4±41.4 msec. The general HRV increased at 12 month since RDN: SDNN from 123.4±41.4 msec to 155.8±51.4 msec (p<0.05), SDANN-i from 105.3±42.7 msec to 122.1±41.1 msec (p<0.05). There was observed increase in RMSSD, reflecting of parasympathetic activity of autonomic nervous system – from 29.7±43.6 msec to 41.1±33.2 msec (p<0.05). The total number of premature supraventricular and ventricular contractions was also significantly decreased both at 6 and at 12 months after RDN (p<0.05 for both cases). Mean 24-hour monitoring heart rate was reduced by 5.8 bpm (p=0.02) at 12 month after RDN. No pauses or conduction abnormalities were observed either at baseline or after RDN. Conclusions Besides the important effect of RDN on heart rate and arrhythmic events, a significant improvement the time domain indexes of HRV was evident in patients with resistant hypertension at 12 month after the RDN-procedure. Our prospective single center study shows that RDN results in substantial BP lowering, significant reduction of mean heart rate and arrhythmia burden and restores autonomic balance in patients with resistant uncontrolled hypertension. Funding Acknowledgement Type of funding source: None